[PATCH RFC RFT v2 1/5] mm: Introduce ARCH_HAS_USER_SHADOW_STACK
From: Mark Brown <broonie@kernel.org>
Date: 2023-11-14 20:06:30
Also in:
linux-kselftest, lkml
Subsystem:
filesystems (vfs and infrastructure), memory management, memory management - core, memory mapping, proc filesystem, the rest, x86 architecture (32-bit and 64-bit) · Maintainers:
Alexander Viro, Christian Brauner, Andrew Morton, David Hildenbrand, Liam R. Howlett, Lorenzo Stoakes, Linus Torvalds, Thomas Gleixner, Ingo Molnar, Borislav Petkov, Dave Hansen
Since multiple architectures have support for shadow stacks and we need to select support for this feature in several places in the generic code provide a generic config option that the architectures can select. Suggested-by: David Hildenbrand <redacted> Signed-off-by: Mark Brown <broonie@kernel.org> --- arch/x86/Kconfig | 1 + fs/proc/task_mmu.c | 2 +- include/linux/mm.h | 2 +- mm/Kconfig | 6 ++++++ 4 files changed, 9 insertions(+), 2 deletions(-)
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 3762f41bb092..14b7703a9a2b 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig@@ -1952,6 +1952,7 @@ config X86_USER_SHADOW_STACK depends on AS_WRUSS depends on X86_64 select ARCH_USES_HIGH_VMA_FLAGS + select ARCH_HAS_USER_SHADOW_STACK select X86_CET help Shadow stack protection is a hardware feature that detects function
diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index ef2eb12906da..f0a904aeee8e 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c@@ -699,7 +699,7 @@ static void show_smap_vma_flags(struct seq_file *m, struct vm_area_struct *vma) #ifdef CONFIG_HAVE_ARCH_USERFAULTFD_MINOR [ilog2(VM_UFFD_MINOR)] = "ui", #endif /* CONFIG_HAVE_ARCH_USERFAULTFD_MINOR */ -#ifdef CONFIG_X86_USER_SHADOW_STACK +#ifdef CONFIG_ARCH_HAS_USER_SHADOW_STACK [ilog2(VM_SHADOW_STACK)] = "ss", #endif };
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 418d26608ece..10462f354614 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h@@ -341,7 +341,7 @@ extern unsigned int kobjsize(const void *objp); #endif #endif /* CONFIG_ARCH_HAS_PKEYS */ -#ifdef CONFIG_X86_USER_SHADOW_STACK +#ifdef CONFIG_ARCH_HAS_USER_SHADOW_STACK /* * VM_SHADOW_STACK should not be set with VM_SHARED because of lack of * support core mm.
diff --git a/mm/Kconfig b/mm/Kconfig
index 89971a894b60..b8638da636e1 100644
--- a/mm/Kconfig
+++ b/mm/Kconfig@@ -1270,6 +1270,12 @@ config LOCK_MM_AND_FIND_VMA bool depends on !STACK_GROWSUP +config ARCH_HAS_USER_SHADOW_STACK + bool + help + The architecture has hardware support for userspace shadow call + stacks (eg, x86 CET, arm64 GCS, RISC-V Zisslpcfi). + source "mm/damon/Kconfig" endmenu
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2.30.2